Internal-combustion motor



r. nmz AND M. scHFEn.

iNTERNAL COMBUSTIUN MQTOR.

APPLICATION FILED IAR. 9.1M?.

Patented Aug. 12, 1919.

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F. KRATZ AND'M. SCHFER.

INTERNAL COMBUSTION MOTOR.

APPLICATION men lnnn.9.ts11.

1 ,3 1 3,090 Patented Aug. 12, 1919.

3 SHEETS-SHEET 2.

r. nmz AND M. scHKFEn.

INTERNAL COMBUSTION MOTOR.

APPLICATION FILED IMI. 9| 19H.

Ptentd Aug. 12, 1919.

3 SHEETS-SHEET 3.

m Nn

New. n i. A r na a l UNITED STATES PATENT OFFICE.

FRANZ KRATZ MAX SCHFER, OF STUTTGART, GERMANY, ASSIG-NORS, BY MESNE ASSIGNMENTS, T0 AMERICAN BOSCH MAGNETO CORPORATION, OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK.

INTERIN'AL-COMZBUSTION MOTOR.

Specification of Letters Patent.

Patented Aug. 12, 1919.

To all whom it may concern.'

Be it known that we,FRANz KRA'rz,a subject of the German Emperor, residing at and whose post-office address is Stuttgart, Schlosstr. 59A, Germany, and MAX SGHFER, a subject of the German Emperor, residing at and whose ost-office address is Stutt art, Aeussere Bc senstr. 107, Germany, avc invented certain new and useful Improvements in Internal-Combustion Motors; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to starting apparatus for internal combustion motors, and more particularly to arrangements f or preventing back fire 1n starting. When 1nternal combustion motors are started with a starting handle, it frequently happens that ignition occurs in the cylinder undergoing compression before the compression stroke therein is completed, thus causing an explosion before the piston passes beyond the zone of possible back fire, that zone extending to the upper dead center of the piston. I n conse uence thereof the cra-nk shaft 1s starte backward with great force, and the starting handle, then coupled with the crank shaft, partakes of this sudden backward movement and may severely'hurt the person cranking the motor.

There are various kinds of safety starting handles intended to obviate this defect, their construction being such that they are automatically uncoupled when the crank shaft starts to turn backward as a result of back fire. However, far greater safety 1s obtained if, instead of obviating the hazardous effect of the backward movement of the handle, the back lireitself is revented. I n arrangements of this kind, t e operator 1s not affected b-y impropler operation of the safet handle, and furt ermore the motor 1s not amaged. The premature lgni'tion oceurring before the piston reaches lts dead center, generally results from lthe fact that in starting the motor, the .spark adjustln device is, by mistake, left 1n its advance position, or in an intermediate position, 1nstead of being set in retarded positlon.

The present invention obvlates the hazardous effect resulting from an incorrect vposition of the spark adjusting device in starting the motor, and at the same time calls the operators attention to his negligence. In accordance with the invention, whenever the periodV of ignition is set to other than retarded position and the starting handle is coupled with the crank shaft of the motor, the ignition system is rendered ineffective to fire the engine, either by opening or short circuiting the generating winding of the ignition device at the period of ignition to which the interrupter is adjusted.

In the accompanying drawings diagrammatically illustratin several embodiments of the invention, w erein, as an example, the circuit of the primary Windin of a magneto is short circuited or opene whenever the period of ignition is set to other than retarded position,

Figures l, 2, 5, 7 and 9 are plan views of several modifications; Figs. 4, 6 and 8 are longitudinal cross sections `of such modifications; Fig. 3 is a detail, and Fig. 10 represents another embodiment of the inventlon.

The screw a connects one terminal of the primary winding b of the magneto to the insulated interrupter element c. The coperative delectable interrupter element d is grounded. The adjustable cam ring f carries the defiecting cam g1, g2.

In Fig. 1, the contact segment lz, is carried by the cam ring but is insulated therefrom, and is connec to the screw a by the conduotor 'e'. The stationary contact spring lc is arranged to disengage the strip h, only when the cam ring is adjusted to retarded osition. The two flanges m of the starting andle Z embrace a longitudinally displaceable rod n secured against rotation. The switch bridge o is carried by the rod 'n in position to bridge the studs and g when the starting handle is couple With the en- Y ine and to disengage. them when uncoupled.

he stud is connected to the spring la through t e Wire r, and the stud g is grounded.

The arrangement illustrated in Fig. 1 opcrates as follows: As long as the starting handle l is uncoupled from the crank shaft of the motor, the normal operation of the ignition system remains unchanged, since t 1e supplementary grounding circuit is interrupted at p, q, even though the segment h and spring le are engaged. However,

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when the starting handle is coupled with thc motor, the studs p and are bridged by o f If, now, the cam4 rin gis in advanced or any intermediate position, the primary winding of Ithe magneto is permanently grounded by way of a, z', ft, k, 9", p, o, g, thus preventing the generation of an ignition voltage in the secondary winding when the interruptor elements d, c are disengaged by the cam g1, g2. As a result of the fact that the operator is prevented by this supplementary grounding circuit from tiring the engine as long as the cam ring is set to advanced or intermediate position, his attention is called to the fact that he has neglected to adjust the period of ignition to the retarded position. )n the other hand, if the interruptor is adjusted to retarded position, the supplementary grounding circuit is interrupted at t, c and the ignition s vstel-n is effective ilor firing the engine when the starting handles` is coupled with the motor.

In Figs. 2 and 3, the insulated spring t', fixed to the cam ring f, contacts with the stationary cam 2 only when the cam ring is adjusted to retarded position. At that time the spring i is bent out ot' engagement with the Contact segment 1,so that the generating winding is effective for ignition, even when the starting handle is coupled with the motor. In advanced and all inter diate positions, the spring z is disengaged from the stationary cani a and there-fore makes contact with the segment so that the generating winding 6 is grounded through the wire r when the starting handle, like in Fig. 1, is coupled with the motor.

In Fig. 4, the supplementary grounding circuit is closed by a spring and' a contact segment both arranged inside the interruptor housing. The grounding switch s is connected in the usualway to the sleeve u in which Vthe brush t is held in engagement with the screw a.. The cam ring j" is adijustably mounted on the casing of the magneto, and has a cover o of insulatin material snugly fitted to the cam ring an having a forlk w embracing the stationary pin 1. The langes 2, 3 of the cam ring carry insulafted oval springs 4, 5 which are connected by the wire 12 and press the contact pins 6, '7 against the conta-ct segments 8, 9 in the cover o. The contact segment 8 is connected by the barl l0 to 'the sieeve u, and thence through the brush if to the screw a.. The segment'is connected through the binding post 11 to the stud p. It will be observed from Fig. 5 that the contact pins 6 and 7 are so located as to be disengaged 'romthe respective segments 8 and .9,when the cam ring is in its retarded position, and to be engaged therewith when the cam ring is in advanced or any intermediate position. Consequently, whenever the adjusting lever is in any position other than rctardedposition, the primary winding b of the magneto is short circuited through the supplementary grounding circuit whenever the starting handle is coupled with the motor.

The connection between the contacts (i, 4 and the binding post l1 might as well be effected directly through the wire 1.2 by employing a spiral wire adapted to elongate in the ratio of the relative movement bctween the cam ring f and the cover o. However, as wire connections of this kind should be avoided as far as possible in i nition devi-ces, the second sliding contact 9 is preferably employed. One of the segments 8 or 9 might be elongated sufiiciently for the respective contact pins 6 or 7 to touch it in the position of advanced ignition also, sinre the opening and closing of the supplementary grounding circuit is controlled only by one of the two sliding contacts.

In Figs. 6 and 7, the conducting member 13 rotates with the. screw a. in electrical connection with the primary Winding and carries the interrupter elements c, d. Two stationary contact segments 15 and 16 are connected with each other by the Wire 17 and with' the binding post 11, and are of such length as to engage the brush 14 throughout the range corresponding to advanced and all positions other than retarded position. Thus when the cam ring is set to retarded position, the primary winding I) is not grounded through the supplementary grounding circuit, but when in advanced or any intermediate position, it is grounded during the period of ignition to thereby render the ignition system ineffective for firing the motor.

Figs. 8 and 9 show an arrangement in which the starting handle cau-ses the primary Winding of the magneto to be opened just previous to the period of ignition instead of short circuiited, whenever, in start` ing the motor, the cam ring is in advanced or any position other than retarded position. The rotating member 13, which in this case is insulated from the screw a, carries a brush 14 co'perating with the four contact segments 18, 19, 20 and 21. The segments 18 and 19 are connected to the screw a by the sleeve u and brush t, and tothe switch stud p by wire 24. The segments 20 and 21 are connected to each other b the wire 22 and to the stud g by wire 23. i.llt-1e switch bridge o is arranged in1 this case in such manner that it normally bridges the studs and g, but disconnects them when-the starting hand'le is coupled with the motor. When the cam ring f is set to retarded position, the interruptor elements c, d are disengaged by the interruptor cam when the brush 14 engages the segments 18 or 19. Just previous to this period of ignition, the circuit of the primary Winding b was closed by Way of a, t, u, 18, 19, 14, 13, c, d, and the interruption immediately following causes the generation of an ignition voltage in the secondary Winding of the magneto, Whether or not the studs p and g were bridged by o. However, when the cam ring is in other than retarded position, the disengagement of the interrupter elements c, d occurs when the brush 14 engages the segment 21 or 20. If, in this case, the starting handle Z is disconnected from the motor, the circuit of the primary Winding b is closed, except at the period of ignition, through a, t, u, 18, 24, p, o, g, 23, 21, 14, 13, c, d. However, ithe starting handle is coupled with the motor, that circuit is open at the switch studs p, g When the interrupter elements c, d are disengaged by the cams, and is closed only When the brush 14 engages the seglnent 18 or 19, corresponding to the retarded position of ignition. Thus, in all positions other than retarded position, the generation of ignition voltages is impossible When the starting handle Z is coupled with the motor, by reason of the fact that the primary circuit is open at the time it ought to be closed in order to build up the armature field.

In Fig. 10, the ignition in starting is generated by a starting magneto, and not by the running or service magneto. This is effected by connectin the starting magneto with the starting han le by means of special gearing, and connecting the ignition circuit to the spark plugs, through the distributer of the service magneto as long as the starting handle is coupled with the crank shaft of the engine, and only during the period of retarded ignition, the service magneto being disconnected. In this arrangement, 30 is the running or service magneto, of which b is the primar Winding, c the interruptor therefor, 32 t evslip ring connected to the secondary Winding 31, and 33 a brush connected to the rotatable brush .34 of the distributer 35. The starting magneto 36 is pro vided with a primary Wmdin 37, an interrupter 38, a secondary Winding 39, a slip rin 40, and a stationary brush 41 connected to ie rotatable brush 42 of the distributer 35. The distributer segments 43, 44, 45, 46

are connected to the spark plu s of the cyll inders I, II, III and IV. e primary Winding b of the service magneto 30 is connected to the stud p ofthe switch having the brid e 0 and the grounded stud g. The starting andle Z has, in addition to the coupling member 47, which is adapted to cooperate With the coupling member 52 on the crank shaft of the motor, a sprocket wheel 48 adapted to drive the chain 49 and the sprocket wheel 50 which is connected through the iexible shaft 51 to the armature shaft of the starting magneto 36. When it is desired to start the motor, the starting handle l is pressed in to engage the coupling members 47, 52. At the same time the bridge 0 bridges the studs p, q to short circuit the service magneto 30. When, now, the handle Z is turned, no current passes through the slip ring 32 to the distributer brush 34, but the starting magneto 36 in being driven by the flexible shaft 51 generates ignition currents which are conducted to the distributor contacts 43, 44, 45, 46 through the rotating brush 42. The relative position of the brushes 34 and 42 is such that the ignition currents generated in the starting igniting device are conducted to the various spark plugs in the period of retarded ignition, so that there is no danger of back fire. As soon as the starting handle is uncoupled from the motor, the studs p, g are disconnected and the starting magneto 36 comes to rest. At the same time, the service magneto 30 starts to generate ignition currents which are conn ducted to the spark plugs of the various cylinders through the rotating distributor brush 34.

The object of the present invention would be attained by controlling the secondary circuit of the lgniting device instead of the primary circuit, as herein shown. However, it generally is preferable to control the n primary circuit, since there is less diiiculty in short circuiting or interrupting the low voltage circuit.

The same device may further be used advantageously in connection with battery ignition devices. In these or other igniting devices in which the interrupter elements are stationar and the cams rotatable, the arrangements ascribed herein must be altered only in so far as the connection of the interrupter to the contact segments can be effected by stationary wires instead of carbon brushes.

Having thus described our invention, what We claim is: 11o

1. In an electric ignition system for internal combustion motors having a starting handle, a switch actuated by the starting handle,Y an adjustable interrupter having cooperative insulated and grounded elements, a contact segment carried by the interrupter, a brush electrically connecting the insulated element to the contact segment, and circuit connections which include the switch and the contact segment and which, when the handle is coupled with the motor to crank it, render the ignition system effective Y to fire the motor only when the interrupter is adjusted to retarded position.

2. In an electric ignition system for internal combustion motors having a starting handle, a switch actuated by the starting handle, a fixed contact segment, an adjustable interrupter for the ignition system,

a bru-sh carried by the rotor of the interi rupter and cooperative with the contact se nient, and circuit connections which inclu e the switch and the contact segment and which, when the handle is coupled with the motor to crank itJ render the ignition stemv effective to fire the engine onl when t e interruptor is adjusted to retar ed position.

3. In an electric ignition system for intei-nal combustion motors havlng a starting handle, a switch actuated by the starting handle, a magneto, a fixed contact segment, an adjustable interruptor for the ma neto, a brush carried by the rotor of the interrupter and cooperative with the contact segment, and circuit connections which include the switch and the contact segment and which, when the handle is coupled with the motor to crank it, render the generating Winding of the magneto effective to fire the engine only when the interruptor is adjusted to retarded position.

4. In an electric ignition system for internal combustion motors havlng a starting handle, aV switch actuated by the starting handle, a magneto having primary and secondary windings, a xed contact segment, an adjustable interruptor for the magneto, a brush carried by the rotor of the interruptor and cooperative with the contact segment, and circuit connections which include the switch and the contact segment and the primary Winding of the ma cto and which, when the handle is couple with the motor to crank it, render the primary winding eifective to generate a sparking voltage in the secondary Winding only when the interruptor is adjusted to retarded position.

5. In an electric ignition system for' i11- ternal combustion motors having a starting handle, a switch actuated by the starting handle, a magneto, a xed contact segment, an adjustable interruptor for the magneto, a brush carried by the rotor of the interruptel" and cooperative with the Contact segment, and circuit connections which include the switch and the contact segment and which, when the handle is cou-pled with the motor to crank it, render the magneto eii'ective to lire the engine only when the interruptor is adjusted to retarded position.

6. In an electric ignition system for internal combustion motors having a starting handle, a switch actuated by the starting handle, an adjustable interruptor having a contact segment and a brush arranged to engage the contact segment in all sparking positions excepting the retarded position of the interrupter, and circuit connections which include the switch and the brush and the contact segment and which, when the mismo handle is coupled with the motor to crank it, render the ignition system e'ective to fire the engine only when the brush is disengago'd from the contact segment.`

7. In an electric ignition system for intermal combustion motors having a starting handle, a switch actuated by the starting handle, an adjustable interruptor for the ignition system, a fixed contact segment, a brush carried fby the rotor of the interruptor and arranged' to engage the contact segment at alle-parking positlons excepting the retarded position, and circuit connections which include the switch and the brush and the con-tact ment and which, when the handle is couped to the' motor to crank it, render the ignition system eifective to fire the engine only when the brush is disengaged from the contact segment.

8. In an electric ignition system for internal combustion motors having -a starting handle, a grounded switch, arranged to be ci'osed when the starting handle is coupled with the motor and to be open when uncoupled, an justable interruptor having a fi'Xed contact segment and a rotating brush arranged to engage.' the contact segment at all sparking positionsexoepting the retarded position, an igniting device having a generating Winding Withv onel terminal grounded and the other terminal connected to the rotwtin brush,- aand circuit connections which lncl'u e the conta-ct segment and the switch so that when the handle is coup-led with the motor to crank it, the iigniting device is grounded at ail sparking positions except` ing the retarded position.

9. In a device of the class described, in combination, an' internal combustion motor, an' electri'c,ignition device operatively connected with said motor, a starting? handle adapted to be temporarily coupled with the shaft of said motor, said ignition device comprising a rotary primary winding, a contact piece* 14 connected to; said wind-ing, counter-contact pieces f5; f6 connected to the rounding contact of said starting: hand e, and means' for causing said contact piece 14 to come' into contact with the said countei-Lcontacts I5, 1,6 only when the motor piston is in the position of advanced ignition.

lin testimony whereof we ax our signatures, in presence of two Witnesses.

FRANZ KRATZ. MAX SCHFER. Witnesses:

Piron Wol-imm', Aeiou' ScHLnRz.

copies of this patent may be obtained for ve cents eaoli, byaddxessin'gi'tlc "Ummislibner el.' Insolite, Washington, ZB. 6.. 

